hi if you cant get any response from ebay seller i would send him an email stating that under the consumer act the item is not fit for purpose and that if he does not get in touch you will do a charge back on him and get all your money back that should make him twinge a little. any brushless controller that is 36v will work if you do buy go for more watts and get a bit more pull from your bike say 36v 750 or 800 watt . ecrazyman on ebay is trustable.